Selective signaling and registering apparatus circuit.



.No. 666,706. Patented Ian. 29, I901. H. E. SHREEVE.

SELECTIVE SIGNALING AND REGISTERING APPARATUS CIRCUIT.

(Application mud'se e. 18, 1900.; (No Model.) 2 Shets-SheetI.

v WITNESSES: INVENTOR.

THE "aims PETERS-CO PHOTO-H1110. wAsmmm La c.

No. 666,706. Phtantad Ian. 29,1901.

u. E. sunsavz.

SELECTIVE SIGNALING AND REGISTERING APPARATUS CIRCUIT. (Application medSept. 16, 1900. (No Model.) g SheeIs-Sheat 2.

WITNESSES: (Q JNVENTOR.

ATTORNEY.

m: "cams wzrzns c0. PHOTO-LIYHOI. WASHINGTON w. c.

UNITED STATES PATENT OFFICE.

HERBERT E. sHREEvE, O DEDHAM, MAssAci-IUsETTs, ASSIGNOR To THE AMERICANBELL TELEPHONE COMPANY, or BOSTON, MASSACHUSETTS;

SELECTIVE SIGNALING AND REGISTERING APPARATUS CIRCUIT.

SPECIFICATION forming part of Letters Patent No. 666,706, dated. January29, 1901.

Application filed $eptember 18, 1900. serial No. 30,427. (No modemassociated with the said substations for opcrating registering or meterdevices arranged to register the connections initiated by thesubscribers at the substations and completed by the operator at thecentral station, and such registering or meter devices may be placed atthe substations or be located at the central station, as may bepreferred.

The presen t invention relates to that class of selective devices forparty-line circuits wherein plus and minus currents may be transmittedat will over either or both conductors of a metallic circuit, theselective translating devices of the substations being connected inbranches to earth from the said main conductors, respectively,substantially as described in Patent No. 644,647, granted to George K.Thompson and Ernest O. Robes and dated March 6, 1900, to which referenceis made, as the devices for sending the operative currents and foroperating the selective translating devices are operated therein as theyare in this invention.

The invention comprises a metallic main circuit extending between acentral station and two substations, so arranged that each mainconductorof the circuit is provided with a principal normally-disunitedbranch divided or split into two grounded subbranches in parallel witheach other, a biased polarized electromagnetic call-bell being includedin one or said grounded branches and a biased polarized electromagneticservice-meter in the second branch at each of the substations that is tosay, at one station the polarized call-bell is in one parallel subbranchof the normally-detached main earth branch associated with one mainconductor, and the polarized service-meter is in the second parallelsubbranch thereof, and at the second station the call-bell and meter arein the respective parallel subbranches of a normally-detached main earthbranch from the second main conductor. A relay-switch at each stationconnected in series with a condenser in a bridge between the mainconductors controls the connection of the main ground branch (andthereby the selective devices in the parallel branches) and theappropriate main conductor, maintaining the normal severance when thecircuit is at rest, uniting the main branch to the main conductor whilethe selective signal and meter currents are being sent from the centralstation to either substation, and again severing the main branch fromthe main conductor after the said currents have been transmitted. Thebridged relay at each substation is a neutral relay-t. 6., non-polarizedand slow in demagnetization-and is so constructed that when asufficiently strong intermittent or alternating current of eitherdirection is caused to pass through itselectromagnetic coils itsarmature is attracted to its forward position and remains attracted aslong as the transmission of such current continues, and the said currentafter operating the relay to close the said main disunited branch isadapted to energize the selective device in one of the said multiplegrounded branches, as hereinafter described.

Keeping in mind the patent of Thompson and Robes, to which reference hasbeen made, wherein four call-bells at as many substations areselectively operated by current-selecting means described herein, it hasbeen discerned that four selective devices may be separately thusoperated without regard to the particular object to be attained, and myinvention is based upon this fact. As a concrete exemplification of theidea this specification discloses a system wherein the call-bells at thetwo substations may be operated by an intermittent plus current and thatthe counting or registering devices may be operated by an intermittentminus current, or vice versa, it being well understood that a differentarrangement is within the scope of the invention.

Referring to the drawings which illustrate the invention, Figure l is adiagram showing a two-party line extending from a central staadapted forinsertion into the spring-jack J,

and when inserted its conducting-surfaces p and p engage the respectivesprings 1 and 2, I

thereby uniting the two main conductors b and a, respectively, to thecord 'circuit-conductors b and 0?.

At each substation there is a normally open telephone-bridge F frompoint 'lG-on conductor a, to point 26 on conductor 1), adapted whenclosed (by the removal of the receivingtelephone from the switch-hook s)to include the switch itself, its contact-point 11, the secondarywinding 3 of the induction-coil I, and

the microphone T, while associated with said a bridge and forming, infact, aparallel branch of a portion thereof is a local circuit extend-Ting by conductor 7 from point 6 on part 50f said bridge F, through thecondenser c to point 8, and thence through the primary winding 4 of saidinduction-coil, and .by con-} ductor 9 through the receivert to theswitch-j point 10. Also at each substation in a bridge between the twomain conductors a and b of the main circuit is a slow discharging ordemagnetizing neutral relay :R, which is adapted to respond to thetransmission over the' two conductors of the main circuit-0f ani-ntermittent selective current by the attraction of its armature d tothe front stop 18 thereof;

and by the steady maintenance of such ,attraction as long .as thecurrent continues.

This bridge is traceable from point 16 on conf ductor a throughconductor 13, secondary coil 3, conductor 14, including the winding: ofrelay R, point 8, conductor 7,-and condenser c to point 26 on conductorb. At-sub-;

station S the armature-d is connected byconductor 17 with point 36 onconductor b,while at substation S the armature d of corre sponding relayR is connected by wire l7 with the point 16 on the .main conductor a.Anyrelay may be employed,as the relays R and R provided its constructionand adjustment is such that when placed in series with a condenser andsubmitted to the actionof an intermittent current,it will under a Widerange of the frequency of the intermissions attract its armaturesteadily to the contactpoint 18 and maintain its positionnotwithstanding the recurrence of an intermission between each twoemissions of current as long as the said current continues.

At substation S and at substation S respectively, are normally open ordisconnected branches 19 and 19*, divided at the point 20 into twosubbranches 21 and 22, shown as being united at point 24 to a commongroundterminal 25, the subbranches 21, containing the call-bells B and Bbiased to respond,

7 say, to positive or plus impulses of current,

and the subbranches'22, containing the service-meters M and M biased orwound to respond to negative impulses of intermittent current. The saidearth branches 19 and 19 are normally discontinuous between thearmatures of the relays R and R and their front stops 18 and 18 owing tothe normallyretracted position of said armatures; but when anintermittent current of either sign from the central station passesthrough the windings-of t'he relays they become energized and attracttheirarmatu restotheir front contacts, and the parallel earth branchesat each substation are closed to their own main conductor, so that theselected call-bell or meter device can then be operated by the action ofthe said current if of the proper direction. Thearmatures of the relaysthus operate as switches to control the grounded branches of thesubstations and to temporarily unite them to the prearranged imainconductors.

It has been 'hereinbefore assumed that the call bells at the twosubstations are to be selectively operated by an intermittent current ofdeterminate sign and that the meter devices at said substations are tobe selectively operated by an intermittent current of opposed signtransmitted from the central-station generator Gon the depression of theappropriate key of the keyboard, and to effect such results with thecall-bells which are of the well-known polarized kind the call-bellarmatures at the respective substations are provided with thebiasing-springs b and b arranged to press upon one end of said armaturesand to hold them in the position to which, if left free, they would beattracted by currents of minussign.

The service-meters each consist of two electromagnets e e ,.the cores ofwhich are yoked togetherand which are polarized by the permanentmagnetf. The windings of these electromagnetsare connected in series,asshown, and so wound that when current flows through themlike poles areadjacent to the armature v. The ;lever.of armature r carries upon itsfreeend a pallet g, adapted to effectuate the revolution ofa-ratchet-wheel h, and thereby operate-registering mechanism of usualcharacter, but not shown. The armature is arranged to be in .a state ofequilibrium normally-or when not attracted and is provided with adelicately-adjustable weight w to counteract any tendency which it mayhave to stick in its forwardposition after the current has ceased toflow through the windings of the electromagnets, which are sluggish indemagnetization and are adapted to hold the armature attracted ,whilethe current is transinitted. The armatures of the service-meters at bothsubstations are thus adapted to respond to intermittent currents ofnegative sign, and when they pass from a state of equilibrium toward thepoles of their electromagnets the pallets cause the register to advanceone half a unit division, and when the armatures fall off upon thecessation of the current the pallets cause the register to advance thesecond half of the unit division, thus recording a unit.

The intermittent-cuwent-transmitting apparatus at the central stationconsists of the keys K, K K and K, with their associated connecting-plugP and currentgei'ierator G. The said plug is adapted to be inserted inthe spring-jack J in order that current from the generator may betransmitted by either of the keys to any one of the selective devices atthe substations. G may be any suitable generator adapted to develop anddeliver to the supply-conductors 30 and 31 intermittent currents ofpositive and negative direction, respectively, by means of thebrush-springs and x, which bear upon the commutator z, which in a mannerwell understood is constructed with a non-conducting and a con ductingportion, each of which passes under thesprings o and 00 once in eachrevolution, and the generator-armature winding has one terminal attachedto the said conducting portion and the other to the metal ring y, onwhich the spring q, 'to which the permanent ground connection E and oneterminal of the generating-helix are connected, continuously bears. Thesprings o and a: are so adjusted that the former is in connection withthe commutator-conductor during the development of current impulses ofone direction or sign and the latter during the development of impulsesof opposite sign. The line-springs of the keys are marked 2' andj andconnect with the keyboard and plug circuit-conductors a and b andthereby with the main conductors a and b, respectively. The earthconductor E is branched by conductor 31 to the operative springs 11 ofthe keys K and K and the operative springs m of keys K and K Thepositive supply-conductor 30 branches to operative springs m and 'n ofthe respective keys K and K and the negative supply-conductor 33 to thesprings m and n of the respective keys K and K In the operation of theinvention if callbell B at substation S is to be rung, the plug P beingin the spring-jack J, the key K is pressed so that the springsj and 2'are brought into contact, respectively, with the springs m and n, thusforming a circuit from the positive brush-spring 0 of the generator, byway of conductor 30, key-springs m andj, conductors b and b, points 26and 6, conductor 7, including the condenser 0, point 8, conductor 14:,including the winding of the relay R, conductor 13, including thesecondary 3 of the ind uction-coil I, main conductors c and akey-springs '2; and n, and conductor 31, to

the earth connection E and thus to the other generator-pole.Steadyingorreducingresistances r r of any necessary magnitude may beintroduced into the cord conductors 3O 33, if desired. An intermittentcurrent of plus sign is thus caused to circulate in the circuit whichhas just been traced, and this current obviously passes to substation Salso,traversing there similar normal circuit arrangements, and therelays R and R are consequently actuated to attract their armatu res d dto their front stops 18 and 18, and thus bring the station earthbranches 21 and 22 at station S, with 21 and 22 at station S into directconductive connection with the respective main conductors a and b.Although both relays operate, the call-bell at station S is alone of allthe devices included in the multiple branches operated, it having beenselected by the use of the key K. The intermittent plus currenttransmitted by the said key K passes to the earth branch 21 at saidstation Sand through the magnet of hell B to earth E, and the bell beingbiased to respond to this particular current rings continuously as longas the key-pressure is maintained, as a sufficient portion of thecurrent leaving conductor b at point 36 passes, via conductor 17,armature d, contact-stop 18, to point 20, and thence by conductor 21 andbell-magnet B to earth E. The meter device M associated with the firstsubstation S does not operate, though its mag-net does receive current,because the said magnet is polarized to be responsive to currents ofopposite sign only, and if the bell-actuating current in said magnet hasany effect at all it is to strengthen the repulsion of the armature. Thebell and register mechanisms at substation S3 both remain unaffected,because, though the relay R at said station is operated, the act ofpressing the key establishes a dead earth E3 on the main conductor athrough the keycontacts 1; and n, which shunts the resistances of themagnets of said mechanisms, so that practically none of the currentreaches the substation earth E or passes through said magnets; but ifthe key K be pressed the call-bell at substation S alone responds, theother translating devices of the circuit remaining quiescent, for inthis case the current impulses of plus sign reach the said bell Bdirectly over the main conductor a, the devices at station S now beingshunted and the meter at station S being irresponsive to currentimpulses of opposite direction. By considering the connections of thekey K it will be seen that on depressing such key the main conductor ais connected with a pole of the generator during the development of plusimpulses at such pole, this occurring by means of the contactestablished between the key-springs 1 and a, while the conductor Z) atthe same time, by the contact between the springs j and m, is at oncegrounded and also connected with the other generator-pole.

To operate the electromagnetic meter deviceM at substation S, the key K?is depressed, the springs 7' and 6 close uponthe respective springs mand n of said key, and a circuit is formed over which intermittentnegative impulses pass as follows: spring-brush p of generator G,conductor 33, springs m and j,'conductorsb and b to points" 26, 36, and26* on the latter conductor, and from point 26 by conductors 7 14, relayR, conductors 13 a a key-springs i and n, conductor 31 to the otherbrush q and earth E 7 Current also passes from point 26 over conductors7 14 and relay R and conductor 13" to main conductora and back to earthE the result being that both relays R and R are energized and attracttheir armature's d and d to their forward contacts 18 and 18*, and apath is made over which current traverses from the point 36 on mainconductor 12 to the earth E over the parallel branches 21 and 22 atsubstation S. As the negative impulses pass through the electromagnets eand c of the meter M at substation S the armature 'v is attracted,causing the pallet g to advance the ratchet-wheel one-half a division ofthe-unit space upon the dial, (not shown,) and owing to the sluggishnessof said magnets the armature is held up to the poles of the magnets,which owing to their construction are both of one polarity, as long asthe pressure of the key and the con sequent transmission of theintermittent current continues; but when the key K is released and thecircuit from the generator G broken the armature falls back and thepallet advances the wheel h the remaining onehalf division, thuscompleting the registration'of a connection on the dial. The currentdoes not alfect the bell B, because it is of sign opposite to thatdesigned for the operation thereof, and the bell B and meter device M atsubstation S are not operated or disturbed, because no operative currentreaches them, they being shunted by the grounding of main conductor a inthe key K through the contact established between the springs 7i and nin the manner indicated in describing the operation of the bells B and BOf course the bell B is further protected by its polarity, and to causethe meter device M at substation S to register a connection the key K ispressed, so that its springsj m and q} n are in contact, a circuit thusbeing formed over which intermittent negative impulses traverse from thespring-brush p of the generator. In this case the main conductor a isbrought into connection with the active generatorpole through thecontact established between 11 and 'n, and main conductor 1) isgrounded.

and also connected with the other pole of said generator. Thesubstation-relays R and Ft both operate; but the meter M only responds.The bell B at the same station is not responsive to negative impulses,and therefore continues quiescent.

The meter at the substation S is shunted from the circuit by the groundestablished in the key K on the main conductor 1), and the bell atsubstation S remains at rest, because it also is shunted by the groundedmain conductor b and also because it is irresponsive to negative orminus current impulses.

InFig. 2 the meter devices are shown as being at the central station andin normally open earth branches from the respective main conductors ofthe circuit. Both branches are adapted to be closed by means of aneutral relay R (having the characteristics of relays R and R at thecentral station, the said re lay being connected in series with acondenser c in a bridge F between the said main conductors. Theselective devices are operated by the depression of the keys shown inthe keyboard, Fig. 1, and precisely the same results are achieved.

I claim-- 1. The combination with the two main conductors of a metallictelephone-circuit connecting two substations with a central station; agrounded source of intermittent current at the central station; and fourkeys controlling the connection of said circuit and source, and adaptedeach to connect the two said main conductors with the two poles of saidsource, and respectively to connect one or the other of the said mainconductors with either the positive or negative commutator- 'brush ofsaid source; of four normally-detached earth branches, a pair for eachmain conductor; a polarized electromagnetic bell in one branch, and anoppositely-polarized electromagnetic call register in the other branchof each pair; and means as indicated for connecting the said branches totheir respective main conductors on the operation of any of the saidkeys, and for transmitting the appropriate current over either mainconductor for the selective operation of the bell or call-registerassociated with the branches thereof; substantially as described.

2. In a telephone system, the combination with the main conductors of ametallic substation-circuit extending between the central station andtwo substations; of a polarized electromagnetic call-bell and anoppositely- -polarized electromagnetic registering device orservice-meter for each substation, connectedin separatenormally-detached earth branches of the said main conductorsrespectively; a slow-acting relay for each substa tion bridged betweenthe said main conductors, and adapted when excited to connect the saidbranches with their appropriate main conductors; and means at thecentral station for simultaneously transmitting over the metalliccircuit and through a grounded circuit comprising a selected one of thetwo main conductors, an intermittent current of either direction asdesired, for the simultaneous operation of the branch-connecting relays,and the selected polarized call-bell or service-meter, substantially asset forth.

3. In a telephone system, the combination with a metallic ordouble-conductor main circuit; and a relay responsive to an intermittentcurrent regardless of direction, and adapted to maintain the steadyattraction of its armature during the passage of such current throughits magnet-coils, the said relay being connected in a bridge of saidmain circuit; of normally-disconnected parallel earth.

branches controlled by the armature of said relay, and unitedtherebywhen in its attracted position to one of the said main-circuitconductors; a polarized electromagnetic bell, and anoppositely-polarized electromagnetic registering device or service-meterconnected in the said two parallel branches, respectively, and adaptedboth to respond to intermittent currents, but of diverse direction; andmeans for transmitting an intermittent current of appropriate directionfor the selective operation of either bell or meter as desired, throughthe grounded circuit formed of the earth branches and that one of themain conductors to which they are united, and through the metalliccircuit formed of both main conductors and the relay simultae neously;substantially as set forth.

4. The combination of a metallic telephonecircuit extending between acentral station and two substations; an earth branch comprising twoparallel conductors associated at each substation with a diiferent mainconductor of said metallic circuit, but normally detached therefrom;sluggish or slow-acting neutral relays, as indicated, one at eachsubstation, bridged between the two main conductors of said metalliccircuit,-and adapted on the excitement of its magnet to switch the saidearth branches into connection with the appropriate main conductors;polarized electromagnetic bells biased or adjusted to respond tointermittent current impulses of definite but relatively indifferentdirection, connected one at each substation in one of the parallel earthbranch conductors thereat; an oppositely-polarized meter or registeringdevice at each substation connected in the other parallel branchconductor thereof, and biased or adjusted to respond to intermittentcurrents opposite in direction to those which operate the bell; andmeans at the central station for transmitting over the appropriate mainconductor intermittent currents of appropriate direction for theselective operation of either bell or meter at either substation; andfor simultaneously transmitting the same current through the metalliccircuit for the operation of the relays; substantially as described.

5. The combination of a metallic telephonecircuit extending between acentral station and two substations; an earth branch divided into twoparallel conductors, associated at each substation with a different oneof the conductors of said main circuit, but normally detached therefrom;a sluggish or slow-acting neutral switching-relay as indicated, at eachsubstation, bridged in series with a condenser between the mainconductors of said circuit, and adapted on the excitement of its helicesto switch the said earth branches of said substation into connectionwith their appropriate main conductor; polarized bells one at eachsubstation biased or adjusted to respond to intermittent currents oflike direction and having their-helices in one of said parallel earthbranch conductors at said substation; polarized meter orcall-registering devices one at each substation adjusted to respond tointermittent currents also of direction like to one another, butopposite to that to which the said bells are adapted to respond; thesaid registering devices at each substation having theirexciting-helices connected in the other parallel branch conductor ofsuch substation; and means at the central station for impressing uponboth main conductors intermittent currents of either direction for theoperation of said relays, and pursuant to the operation of said relays,upon either main -conductor currents of appropriate direction for theselective operation of either bell or registering device at eitherstation; as set forth.

6. In a telephone-signaling and meter system and apparatus, thecombination with a metallic or double-conductor main circuit, of earthbranches extending from the said maincircuit conductors but normallydetached therefrom; sluggish or slow-acting neutral relays as indicatedbridged in series with a .condenser between the main conductors of saidcircuit, and adapted on the excitement of their helices to switch thesaid earth branches respectively into connection with their appropriateconductor; polarized bells and polarized meter devices, equal in number,having their helices in the said earth branches of the two mainconductors respectively, the bells biased or adjusted to respond tointermittent currents of one sign or direction, and the meters biased oradjusted to respond to similar currents of opposite sign or direction;and means at the central station for impressing upon the two mainconductors composing in series the said main circuit intermittentcurrents of either direction for the operation of the said relays andthe consequent connection of the earth branches, and for simultaneouslytransmitting intermittent currents of definite direction over either oneof the said main conductors and its earth branch continuations for theselective operation of the predetermined station bell or meter device;substantially as set forth.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing Witnesses, this 13th day of September, 1900.

HERBERT E. SHREEVE.

Witnesses:

GEO. WILLIS PIERCE, JOSEPH A. GATELY.

ICC

